AMD-761 Datasheet, PDF (228/264 Pages) Advanced Micro Devices – AMD-761-TM System Controller Software/BIOS Design Guide

Preliminary Information
AMD-761™ System Controller Software/BIOS Design Guide
24081D—February 2002
Registers
-----
Bits
Description
0x0x0x4Ch
PCI Control
31:04 Reserved
4:3 Reserved
2
PCI_DT_En
1
PCI_OR_EN
0
Func1_En
0x0x0x50h
31:24
23:20
19:16
AMD Athlon™ System Bus
Dynamic Compensation
Reserved
PVal
NVal
15:12 Byp_P
11:8 Byp_N
7:5 SlewCntl
4
Byp
3:0 Reserved
Initialized/
Required
Value
Actual
Value
Key fcn( )
Notes
0000h
00b
0b
0b
0b
r
B
Must be set by BIOS
0= Disable Delayed
B
Transactions
1= Enable Delayed
Transactions
0= Disable Ordering Rules
Compliance
B
1 = Enable PCI Ordering
Rules Compliance
B
1= Enable 0x0x1xRR Access
00h
r
yh
c
P Transistor Value in Use
yh
c
N Transistor Value in Use
0h
B
P Transistor Value Used if
Byp = 1
0h
B
N Transistor Value Used if
Byp = 1
011b
B
0b
B
1 = Enable Byp_P and Byp_N
0h
r
KEY:
B= Mandatory BIOS function
A= AGP setup by BIOS
c = Calculated/set by AMD-761™ internal logic
P= Power management setup by BIOS o = Setup by OS or OS driver F = Performance enhancement set by BIOS
r = Hardcoded and reserved
u = PCI operational user interface E = Elective BIOS function
216
Recommended BIOS Settings
Chapter 7